X-rays use ionizing electromagnetic radiation to produce images, working like a camera but using radiation instead of light to expose film. The more radiation that passes through an object, the darker the image appears, allowing x-rays to show bones in white since they absorb radiation. X-rays are used to diagnose injuries, treat cancer, and for airport security screening, but carry small radiation risks of about 40 millirems per scan, with an annual safety limit of 360 millirems.